scholarly journals Flavanonol Glycosides from the Stems of Myrsine seguinii and Their Neuroprotective Activities

2021 ◽  
Vol 14 (9) ◽  
pp. 911
Author(s):  
Hee-Ju Lee ◽  
Eun-Jin Park ◽  
Ba-Wool Lee ◽  
Hyo-Moon Cho ◽  
Thi-Linh-Giang Pham ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Spectroscopic Data ◽  
Folk Medicine ◽  
Neuroprotective Activity ◽  
Ionization Mass ◽  
Aβ Peptide ◽  
Ht22 Cells ◽  
Aβ Peptides ◽  
Chemical Structures ◽  
Inflammatory Conditions

The accumulation of amyloid beta (Aβ) peptides is common in the brains of patients with Alzheimer’s disease, who are characterized by neurological cognitive impairment. In the search for materials with inhibitory activity against the accumulation of the Aβ peptide, seven undescribed flavanonol glycosides (1–7) and five known compounds (8–12) were isolated from stems of Myrsine seguinii by HPLC-qTOF MS/MS-based molecular networking. Interestingly, this plant has been used as a folk medicine for the treatment of various inflammatory conditions. The chemical structures of the isolated compounds (1–12) were elucidated based on spectroscopic data, including 1D and 2D nuclear magnetic resonance (NMR), high-resolution electrospray ionization mass spectrometry (HRESIMS) and electronic circular dichroism (ECD) data. Compounds 2, 6 and 7 showed neuroprotective activity against Aβ-induced cytotoxicity in Aβ42-transfected HT22 cells.

scholarly journals Natalenamides A–C, Cyclic Tripeptides from the Termite-Associated Actinomadura sp. RB99

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 3003 ◽  
Author(s):  
Seoung Rak Lee ◽  
Dahae Lee ◽  
Jae Sik Yu ◽  
René Benndorf ◽  
Sullim Lee ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cyclic Peptides ◽  
Culture Broth ◽  
Resonance Spectroscopy ◽  
Ionization Mass ◽  
Inhibitory Effects ◽  
Associated Bacteria ◽  
Chemical Structures ◽  
New Compounds ◽  
Powerful Strategy

In recent years, investigations into the biochemistry of insect-associated bacteria have increased. When combined with analytical dereplication processes, these studies provide a powerful strategy to identify structurally and/or biologically novel compounds. Non-ribosomally synthesized cyclic peptides have a broad bioactivity spectrum with high medicinal potential. Here, we report the discovery of three new cyclic tripeptides: natalenamides A–C (compounds 1–3). These compounds were identified from the culture broth of the fungus-growing termite-associated Actinomadura sp. RB99 using a liquid chromatography (LC)/ultraviolet (UV)/mass spectrometry (MS)-based dereplication method. Chemical structures of the new compounds (1–3) were established by analysis of comprehensive spectroscopic methods, including one-dimensional (1H and 13C) and two-dimensional (1H-1H-COSY, HSQC, HMBC) nuclear magnetic resonance spectroscopy (NMR), together with high-resolution electrospray ionization mass spectrometry (HR-ESIMS) data. The absolute configurations of the new compounds were elucidated using Marfey’s analysis. Through several bioactivity tests for the tripeptides, we found that compound 3 exhibited significant inhibitory effects on 3-isobutyl-1-methylxanthine (IBMX)-induced melanin production. The effect of compound 3 was similar to that of kojic acid, a compound extensively used as a cosmetic material with a skin-whitening effect.

scholarly journals Isolation and Purification of Bioactive Compounds from the Stem Bark of Jatropha podagrica

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 889 ◽  
Author(s):  
Truong Minh ◽  
Tran Xuan ◽  
Hoang-Dung Tran ◽  
Truong Van ◽  
Yusuf Andriana ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ethyl Acetate ◽  
Gallic Acid ◽  
Bioactive Compounds ◽  
Stem Bark ◽  
Ionization Mass ◽  
Methyl Gallate ◽  
Antioxidant Power ◽  
Isolation And Purification ◽  
Chemical Structures

This paper reports the successive isolation and purification of bioactive compounds from the stem bark of Jatropha podagrica, a widely known medicinal plant. The ethyl acetate extract of the stem bark exhibited the strongest antioxidant activity assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and ferric reducing antioxidant power (FRAP) assays (IC50 = 46.7, 66.0, and 492.6, respectively). By column chromatography (CC) with elution of hexane and ethyl acetate at 8:2, 7:3, and 6:4 ratios, the isolation of this active extract yielded five fractions (C1–C5). Chemical structures of the constituents included in C1–C5 were elucidated by gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR) and resolved as methyl gallate (C1, C2, C3, C4), gallic acid (C1, C2), fraxetin (C2, C3, C4, C5), and tomentin (C3). Mixture C2 (IC50 DPPH and ABTS = 2.5 µg/mL) and C3 (IC50 FRAP = 381 µg/mL) showed the highest antioxidant properties. Among the isolated fractions, C4 was the most potential agent in growth inhibition of six bacterial strains including Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Bacillus subtilis, and Proteus mirabilis (MIC = 5, 20, 30, 20, 25, and 20 mg/mL, respectively). All identified constituents exerted an inhibitory activity on the growth of Lactuca sativa, of which the mixture C3 performed the maximal inhibition on shoot (IC50 = 49.4 µg/mL) and root (IC50 = 47.1 µg/mL) growth. Findings of this study suggest that gallic acid, methyl gallate, fraxetin, and tomentin isolated from J. podagrica possessed antioxidant, antibacterial, and growth inhibitory potentials.

scholarly journals A new tetracyclic diterpenoid from the seeds of Euphorbia lathyris

2020 ◽  
Vol 44 (5-6) ◽  
pp. 322-325
Author(s):  
Lie-Feng Ma ◽  
Yue Zhang ◽  
Xuan Zhang ◽  
Meng-Jia Chen ◽  
Zha-Jun Zhan ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
High Resolution ◽  
Spectroscopic Data ◽  
Resonance Spectroscopy ◽  
Ionization Mass ◽  
Two Dimensional ◽  
Detailed Interpretation ◽  
A Minor ◽  
Euphorbia Lathyris

Eupholathone, a minor diterpenoid with an unusual tetracyclic skeleton, was obtained from the seeds of Euphorbia lathyris, along with two known lathyrane diterpenoids, euphorbia factors L2 and L3. The structure of eupholathone was elucidated by detailed interpretation of its spectroscopic data, especially two-dimensional nuclear magnetic resonance spectroscopy and high-resolution electrospray ionization mass spectrometry.

scholarly journals Photocatalytic Degradation of Trifluralin, Clodinafop-Propargyl, and 1,2-Dichloro-4-Nitrobenzene As Determined by Gas Chromatography Coupled with Mass Spectrometry

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Niyaz A. Mir ◽  
A. Khan ◽  
M. Muneer ◽  
S. Vijayalakhsmi
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Photocatalytic Degradation ◽  
Degradation Mechanism ◽  
Gas Chromatography Mass Spectrometry ◽  
Ionization Mass ◽  
Water Medium ◽  
Fragmentation Pattern ◽  
Chemical Structures ◽  
Clodinafop Propargyl

Phototransformation is considered one of the most key factors affecting the fate of pesticides. Therefore, our study focused on photocatalytic degradation of three selected pesticide derivatives: trifluralin (1), clodinafop-propargyl (2), and 1,2-dichloro-4-nitrobenzene (3). The degradation was carried out in acetonitrile/water medium in the presence of titanium dioxide (TiO2) under continuous purging of atmospheric air. The course of degradation was followed by thin-layer chromatography and gas chromatography-mass spectrometry techniques. Electron ionization mass spectrometry was used to identify the degradation species. GC-MS analysis indicates the formation of several intermediate products which have been characterized on the basis of molecular ion, mass fragmentation pattern, and comparison with NIST library. The photocatalytic degradation of pesticides of different chemical structures manifested distinctly different degradation mechanism. The major routes for the degradation of pesticides were found to be (a) dealkylation, dehalogenation, and decarboxylation, (b) hydroxylation, (c) oxidation of side chain, if present, (d) isomerization and cyclization, (e) cleavage of alkoxy bond, and (f) reduction of triple bond to double bond and nitro group to amino.

scholarly journals Four New Acyclic Diterpenes From Siegesbeckia orientalis

2021 ◽  
Vol 16 (11) ◽  
pp. 1934578X2110561
Author(s):  
Do Thi Trang ◽  
Phan Thi Thanh Huong ◽  
Nguyen Thi Cuc ◽  
Duong Thi Dung ◽  
Bui Thi Thu Trang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
High Resolution ◽  
Xanthine Oxidase ◽  
Ionization Mass ◽  
Oxidative Reaction ◽  
Chemical Structures ◽  
Aerial Parts ◽  
Extensive Analysis ◽  
Siegesbeckia Orientalis

Four new acyclic diterpenes, siegetalises A-D (1-4), were isolated from the aerial parts of Siegesbeckia orientalis. Their chemical structures were elucidated by extensive analysis of high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance spectral data. The effects of the isolated compounds on the activity of xanthine oxidase were evaluated by the oxidative reaction with xanthine as a substrate. At a concentration of 50 µM, compounds 1-4 exhibited xanthine oxidase inhibitory activity at levels of 13.59% ± 0.51%, 19.64% ± 1.54%, 17.45% ± 1.26%, and 21.36% ± 1.40%, respectively.

scholarly journals Antimicrobial Lavandulylated Flavonoids from a Sponge-Derived Streptomyces sp. G248 in East Vietnam Sea

Marine Drugs ◽  
2019 ◽  
Vol 17 (9) ◽  
pp. 529 ◽  
Author(s):  
Cao ◽  
Trinh ◽  
Mai ◽  
Vu ◽  
Le ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Antimicrobial Activity ◽  
Mycobacterium Tuberculosis ◽  
Spectroscopic Data ◽  
Inhibitory Concentration ◽  
Culture Broth ◽  
Ionization Mass ◽  
Streptomyces Sp ◽  
Mycobacterium Tuberculosis H37rv

Three new lavandulylated flavonoids, (2S,2′’S)-6-lavandulyl-7,4′-dimethoxy-5,2′-dihydroxylflavanone (1), (2S,2′’S)-6-lavandulyl-5,7,2′,4′-tetrahydroxylflavanone (2), and (2′’S)-5′-lavandulyl-2′-methoxy-2,4,4′,6′-tetrahydroxylchalcone (3), along with seven known compounds 4–10 were isolated from culture broth of Streptomyces sp. G248. Their structures were established by spectroscopic data analysis, including 1D and 2D nuclear magnetic resonance (NMR), and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). The absolute configurations of 1–3 were resolved by comparison of their experimental and calculated electronic circular dichroism spectra. Compounds 1–3 exhibited remarkable antimicrobial activity. Whereas, two known compounds 4 and 5 exhibited inhibitory activity against Mycobacterium tuberculosis H37Rv with minimum inhibitory concentration (MIC) values of 6.0 µg/mL and 11.1 µg/mL, respectively.

scholarly journals Araliachinoside A: A New Triterpene Glycoside From Aralia chinensis Leaves

2020 ◽  
Vol 15 (9) ◽  
pp. 1934578X2095275
Author(s):  
Pham Hai Yen ◽  
Nguyen Thi Cuc ◽  
Phan Thi Thanh Huong ◽  
Nguyen Xuan Nhiem ◽  
Nguyen Thi Hoai ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
High Resolution ◽  
Inhibitory Concentration ◽  
In Vitro Assay ◽  
Ionization Mass ◽  
Vitro Assay ◽  
Chemical Structures ◽  
Hepg2 Cell Lines

From the leaves of Aralia chinensis, 3 oleanane-type triterpene glycosides have been isolated, including 1 new glycoside, 3β,23 -dihydroxyolean-12-ene-28-oic acid 3 -O-β-d-glucopyranosyl-(1→3)- α-l-arabinopyranosyl-(1→3)-β-d-glucuronopyranoside 28 -O-β-d-glucopyranosyl ester (named as araliachinoside A, 1), and 2 known ones, 3β,23 -dihydroxyolean-12-ene-28-oic acid 3 -O-α-l-arabinopyranosyl-(1→3)- β-d-glucuronopyranoside 28 -O-β-d-glucopyronosyl ester (2) and 3β-hydroxyolean-12-ene-28-oic acid 3 -O-β-d-glucurono pyranoside 28 -O-β-d-glucopyronosyl ester (3). Their chemical structures were elucidated by using a combination of high-resolution electrospray ionization-mass spectrometry, 1-dimensional and 2-dimensional nuclear magnetic resonance spectral data, and by comparison with previous literature. Compounds 1-3 displayed cytotoxic activity toward KB and HepG2 cell lines with half-maximal inhibitory concentration values ranging from 8.1 ± 0.1 to 15.7 ± 0.3 µM in in vitro assay.

scholarly journals Mapping and quantifying isomer sets of hydrocarbons ( ≥  C<sub>12</sub>) in diesel exhaust, lubricating oil and diesel fuel samples using GC  ×  GC-ToF-MS

2018 ◽  
Vol 11 (5) ◽  
pp. 3047-3058 ◽  
Author(s):  
Mohammed S. Alam ◽  
Soheil Zeraati-Rezaei ◽  
Zhirong Liang ◽  
Christopher Stark ◽  
Hongming Xu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Diesel Fuel ◽  
Diesel Exhaust ◽  
Impact Ionization ◽  
Exhaust Emissions ◽  
Lubricating Oil ◽  
Ionization Mass ◽  
Analytical Technique ◽  
Chemical Structures ◽  
Tof Ms

Abstract. Airborne particles and vapours, like many other environmental samples including water, soils and sediments, contain complex mixtures of hydrocarbons, often deriving from crude oil either before or after fractionation into fuels, lubricants and feedstocks. Comprehensive 2D gas chromatography time-of-flight mass spectrometry (GC × GC-ToF-MS), offers a very powerful technique that separates and identifies many compounds in complicated hydrocarbon mixtures. However, quantification and identification of individual constituents at high ionization energies would require hundreds of expensive (when available) standards for calibration. Although the precise chemical structure of hydrocarbons does matter for their environmental impact and fate, strong similarities can be expected for compounds having very similar chemical structures and carbon numbers. There is, therefore, a clear benefit in an analytical technique which is specific enough to separate different classes of compounds and to distinguish homologous series while avoiding the need to handle each isomer individually. Varying EI (electron impact) ionization mass spectrometry significantly enhances the identification of individual isomers and homologous compound groups, which we refer to as “isomer sets”. Advances are reported in mapping and quantifying isomer sets of hydrocarbons (≥ C12) in diesel fuel, lubricating oil and diesel exhaust emissions. By using this analysis we report mass closures of ca. 90 and 75 % for diesel fuel and lubricating oil, and identify 85 and 75 % of the total ion current for gas- and particulate-phase diesel exhaust emissions.

scholarly journals Simultaneous Separation and Purification of Five Polymethoxylated Flavones from “Dahongpao” Tangerine (Citrus tangerina Tanaka) Using Macroporous Adsorptive Resins Combined with Prep-HPLC

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2660 ◽  
Author(s):  
Zhenqing Li ◽  
Ziyan Zhao ◽  
Zhiqin Zhou
Keyword(s):  
Mass Spectrometry ◽  
Citrus Fruit ◽  
Gradient Elution ◽  
Ultra Performance Liquid Chromatography ◽  
Water Soluble ◽  
Ionization Mass ◽  
Separation And Purification ◽  
Plant Materials ◽  
Chemical Structures ◽  
Polymethoxylated Flavones

In this study, a preparative separation method was established to simultaneously isolate the polymethoxylated flavones (PMFs) from the peel of “Dahongpao” tangerine using macroporous adsorptive resins (MARs) combined with prep-HPLC. The total PMFs were enriched using MARs to remove most sugars, water-soluble pigments, and flavanones, and the eluents obtained were analyzed by ultra-performance liquid chromatography (UPLC) to determine the PMF composition. The separation and purification of PMFs were carried out by using a mass spectrometry-guided prep-HPLC with a gradient elution of acetonitrile-water (v/v), simultaneously. The purity of these PMFs was determined by UPLC, and their chemical structures were confirmed by electrospray ionization mass spectrometry (ESI-MS-MS), ultraviolet (UV), and nuclear magnetic resonance (NMR). Using the present method, five PMFs, including 5,6,7,4’-tetramethoxyflavone (1), nobiletin (2), tangeretin (3), sinensetin (4), and 5-hydroxy-6,7,8,3’,4’-pentamethoxyflavone (5), can be purified simultaneously, and the purity of the compounds obtained were 95.3%, 99.7%, 99.5%, 98.9%, and 98.1%, respectively. The method reported here is simple, rapid, and efficient, and it can be used to separate PMFs from citrus fruit peels and, potentially, other plant materials.

The in situ analysis of organic matter in soils

2001 ◽  
Vol 81 (3) ◽  
pp. 249-254 ◽  
Author(s):  
Morris Schnitzer
Keyword(s):  
Mass Spectrometry ◽  
Organic Matter ◽  
Solid State ◽  
In Situ Analysis ◽  
Ionization Mass Spectrometry ◽  
Field Ionization ◽  
Ionization Mass ◽  
Chemical Structures ◽  
C Nmr

Traditionally, studies on soil organic matter (SOM) begin with the extraction of SOM from soils, its fractionation into humic acid, fulvic acid, and humin, followed by de-ashing of each fraction. These are tedious, laborious and inefficient procedures that do not provide any chemical information on these materials. Instead, recently developed methods such as solid-state 13C NMR and pyrolysis – field ionization mass spectrometry (Py-FIMS) can now be used for the in situ analysis of SOM in soils. These methods identify the major chemical components of SOM without extractions and fractionations, and yield valuable information on the main chemical structures in these materials. A better knowledge of the structural chemistry of SOM will help SOM chemists and other soil scientists to better understand the complex chemical and biochemical reactions that occur in soils, and will enable them to develop practices that will improve soil management and soil productivity. Key words: Extraction, fractionation, solid state 13C NMR, pyrolysis-field ionization mass spectrometry, chemical composition

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